Conventionally, for an insulated wire used in a vehicle such as an automobile, and electric/electronic equipment, there is widespread use of an insulated wire which includes a conductor prepared by stranding a plurality of elemental wires made from pure copper such as tough pitch copper.
Recently, the performance of a vehicle such as an automobile, and an electric/electronic equipment has been rapidly improved, increasing the number of various control circuits and other components used therein, and accompanied with this increase, the number of insulated wires used therein is also increasing.
In the field of automobiles, weight reduction of a vehicle is desired from the viewpoint of energy saving. Hence, as part of the weight reduction of a vehicle, attempts to achieve weight reduction of an insulated wire have been made. For example, weight reduction of a conventional insulated wire has been achieved by reducing the diameter of a conductor included therein because the conventional insulated wire has sufficient current-carrying capacity.
However, there is a problem that the insulated wire decreases in strength when the diameter of the conductor is reduced. Hence, attempts have been made to improve the strength of the insulated wire including the conductor having the reduced diameter.
For example, a conductor of an automotive electric wire which is prepared by stranding a plurality of elemental wires made from stainless steel and an elemental wire made from copper in combination is disclosed in Japanese Patent Application Unexamined Publication No. 2004-207079.